PSU Computer powers itself on???!

Hi all,

I'm new to this forum but im after a bit of advice because I've tried everything I can think of.

Recently my PSU in my desktop burnt out so I ordered a new one and connected it all up no problem, just as the old one was. However when I switched the power on the back of the PSU unit it powered the computer up without me pressing the button on the front!? The fans all start and I can hear the HDD spin up but nothing ever appears on the screen. The lights on the front of the unit (power & HDD) both stay on constantly and the only way to turn it off is to switch the switch on the back off the PSU, the button on the front doesnt work?

I have tried so many different things i've run out of ideas.

If anyone can help i'd be really grateful. Need anymore info just say

Cheers

Nick

 

What have you tried?

My first thought would be that the pins the front power switch connects to are somehow being shorted.
Though I admit this wouldn't explain why the computer doesn't fully boot up.

Have you checked the motherboard thoroughly to ensure the blown (if it did blow) PSU didn't cause any (visible) damage?

 

motherboard damage or power pin damage. also are you running a dedicated gpu ? as it might have died

 

yeah gonna have to narrow it down.. take the board out on a table- connect the psu, harddrive and leave the video card in

reset the cmos with the jumper or pop out the battery for a minute.. remove all but one stick of ram, see if you can get her to boot.. that should be the bare basics- it maybe hardware was damaged when the psu went (spike)

if that does'nt work.. cycle through your remaining memory sticks one at a time- it won't be the cpu.. if that doesn't work, hook up a speaker to your board (if it already doesn't have one) and there will be a series of beeps you can look up

make sure everything is connected up properly, including the extra 4/8 pin to the mb.. go over all that in your manual.. if your not getting any beeps, it will be either the new psu (unlikely) or the motherboard that needs to be rma'd

you can also test the psu voltage with a ohmmeter

 

Looks like something's shorting somewhere (can happen after you move things around) or the PSU damaged mobo/ram when it bit the dust. Best bet is to start testing the bare essentials out the case like thehippoz suggested.

 

brass stand offs under the mobo ?

 

Thanks for all the advice guys. will try whats been suggested and get back to you.

Cheers